In the prior art, the ratchet socket spanner is formed by a ratchet spanner and a socket. In use the socket is engaged to the ratchet spanner. There are various kinds of sockets for fitting different kinds of screw devices. Thus, the ratchet spanner is engaged to different sockets according to the screw device to be driven.
However the prior art ratchet socket spanner has the following disadvantages. Firstly, there are many sockets being engaged to the ratchet spanner. Thereby, it is necessary to detach and attaché the sockets frequently so that the teeth of the ratchet spanner and sockets are easy to wear and thus the engagement of the socket and the ratchet spanner is loose. In use, the force cannot be effectively transferred to the screw device. It is possible the ratchet spanner slides along the outer surface of the socket so that the force is not transferred to the driving object. Moreover if it is desired to drive an object in a deep place, it may be that several sockets must be serially connected. These sockets are connected one by one. The connection of different sockets is performed by a C ring in one socket to clamp another socket. However it is difficult to withdraw one socket from another socket, especially as the user's hand is oiled. As a whole, the prior art design is not an ideal one and it necessary to be improved.